The present application is based on and incorporates herein by reference Japanese Patent Application No. 2001-5549 filed on Jan. 12, 2001.
1. Field of the Invention
The present invention relates to a mounting structure for incorporating a seat occupant sensor in a seat of a vehicle.
2. Related Art
It is known that a seat occupant sensor is incorporated in a seat of a vehicle for detecting whether an occupant is present on the seat and, if any, whether the occupant is an adult or a child. The seat occupant sensor is arranged between the foam and the trim of the seat, and includes a plurality of sensor cells printed on a film. The sensor cells are connected to an ECU via signal lines also printed on the film.
Since a groove for fastening the trim is formed on the foam and the ECU is installed on the rear end portion of the foam, the signal lines that connect between the sensor cells and the ECU must cross the groove. Then, referring to FIG. 6, it is proposed that a portion of the groove 110 where the signal line 100 crosses the groove 110 is filled up. However, the trim 130 cannot be pulled into the filled portion of the groove 110, and therefore the portion of the trim 130 corresponding to the filled portion of the groove 110 will get wrinkled. Further the filled portion of the groove 110 limits the design of the seat.
Moreover, referring to FIG. 7, it is proposed that the signal lines 100 pass under a wire 120 that passes through the groove 110. However in this case, when the foam 140 deforms, the film may jackknife and consequently the signal line 100 may be broken, because the film cannot move freely in the groove 110. Accordingly the reliability and the durability of the seat occupant sensor are not ensured in this case.
The present invention has an object to provide a mounting structure for incorporating a seat occupant sensor in a seat so that the reliability and the durability of the sensor are ensured and the design of the seat is not spoiled.
According to the present invention, a mounting structure for a seat occupant sensor includes a seat and the seat occupant sensor. The seat includes foam and trim that covers the foam. The seat occupant sensor is disposed between the foam and the trim of the seat for detecting load on the seat, and a signal line is connected to the seat occupant sensor. A groove is formed on the foam, and a first wire attached to the trim passes through the groove. Further a second wire is buried in the foam so as to run along and under the groove. The signal line falls down and thereafter goes up along the inner wall of the groove so as to cross the groove, and the turning-back portion of the signal line passes under the first wire.
A deeper portion is formed on the bottom of the groove so as to correspond to the portion of the groove where the signal line crosses the groove. Further the second wire is removed from the deeper portion so that the turning-back portion of the signal line can move freely in the deeper portion.
Preferably, the portion of the second wire corresponding to the deeper portion is routed so that the second wire bypasses the deeper portion. Alternatively, the portion of the second wire corresponding to the deeper portion may be cut off.